A cell line which is tumorigenic and transformed may not be capable of forming metastases. Using DNA mediated gene transfer, we will attempt to confer the metastatic potential upon benign tumor cells. We have found that NIH 3T3 cells transformed by certain viral oncogenes are metastatic. This result which indicates that metastatic potential can be transferred in this one instance should allow us to extend these observations to other cell types and to develop selection schemes for metastatic potential which will allow us to utilize gene transfer systems to isolate genes which may cause metastatic behavior.